Demagnetization system for magnetizable article packager



E. l. ODELL 2,996,863

2 Sheets-Sheet 2 nmozouwmy mic. m m n m o omhwmmu Aug. 22, 1961 DEMAGNETIZATION SYSTEM FOR MAGNETIZABLE ARTICLE PACKAGER Filed May 21, 1959 INVENTOR EUGEN E I. ODELL BY %w WW ATTORNEYS United States Patent 2,996,863 DEMAGNETIZATION SYSTEM FOR MAGNETIZ- ABLE ARTICLE PACKAGER Eugene I. Odell, Grand Haven, Mich., assignor, by mesne assignments, to Stuart Otto, Westport, Conn.

Filed May 21, 1959, Ser. No. 814,901 12 Claims. (Cl. 53--236) This invention relates to a demagnetization system for packaging machines adapted for packaging magnetizable articles such as nails and the like.

Some development has been done in the packaging of magnetizable articles by electromagnetic means. The development made along these lines is best illustrated by such patents as Gamper 1,330,113 and Otto 2,602,942.

The Otto Patent 2,602,942 discloses a vertical chute adapted to receive on its lower end a container for receiving the nails. At the lower end of the chute is located an electromagnet which produces a field that orients the nails in parallel relationship in the box. In this type of machine, however, the nails are suspended loosely in parallel relationship with one another until the electromagnets are deenergized. However, upon deenergizing the electromagnet, the nails tend to sag and therefore lose their parallel orientation.

The sagging of the nails adversely affects the neat packing of the nails in parallelism within the container. Various attempts have been made to demagnetize substantially instantaneously by reversing the direction of the current flowing through the windings of the electromagnets. To this end, it has been proposed to use separate windings, one for magnetizing and the other for demagnetizing. These separate windings are arranged to produce opposite polarities. This also has not been completely satisfactory since the number of windings required is twice that required by a single winding. As a result, it is highly desirable that a single winding be used; however, this creates a problem of reversing the polarity of the electromagnet in a sufliciently short time so that the nails dont sag during the interval between magnetizing and complete demagnetization of the electromagnet.

An object of this invention is to provide a demagnetization system for demagnetizing the electromagnet so as to minimize the amount of sag of the nails during the demagnetization step.

Another object of this invention is to provide such a demagnetizing system which utilizes a single set of windings and by which the overloading of the line is substantially eliminated.

Still another object of this invention is to provide a nail packaging machine in which the nails are orientated in parallel relationship between the two poles of the electromagnet and a demagnetizing means is provided for almost instantaneously demagnetizing the electromagnet whereby the nails fall straight downwardly into parallel relationship.

Other objects of this invention will become obvious upon reading the following specification in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of the overall packaging machine for magnetizable articles.

FIG. 2 is a partial enlarged view of a portion of the machine of FIG. 1 located between the two electromagnetic poles.

FIG. 3 is a schematic circuit diagram of the demagnetization system utilized in the machine of FIG. 1.

FIG. 4 is a time graph of the voltages across the windings of the electromagnet of the machine of FIG. 1.

FIG. 5 is a time graph of the current flowing through the windings of the electromagnet of the machine of FIG. 1.

Briefly this invention rel-ates to apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container. At the. lower end of the chute is an electromagnet for producing a magnetic field across the chute to orient the objects before they are fully received by the container. This electromagnet has a single winding means adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof. Means is provided to produce a flow of current through the windings in the one direction for a time interval sufiicient to permit orientation of the objects in the chute. Thereafter means is also provided to shut off flow of current in the said one direction. Connected to the circuit of the windings is a separate means for discharging the circuit from the windings. Thereafter means is provided for producing a flow of current through the windings in the reverse direction whereby the demagnetization of the electromagnet is accelerated.

Preferably means is provided which is responsive to' a predetermined current flowing in the one direction through the windings for controlling the reverse flow of the current. Thus the reverse flow of the current is not brought in before the windings can accommodate such current and as a result an overload of the winding in the entire system is prevented.

Within the narrow aspects of this invention the means for discharging the current comprises a discharge resistor shunting the windings for discharging the power when shut cit. The control means for the reverse flow of the current includes a relay coil which at a predetermined decrease in the current flowing in the windings brings into operation the reverse circuit. Other more specific details of this invention are also considered to be included within the narrower aspects of this invention.

Referring to the drawings, FIG. 1 illustrates the over all apparatus which includes a support frame 1 supporting the magnet 2 which includes the poles 3 and 4. The poles 3 and 4 are L-shaped and connected together at their lower ends by the magnetic conduct-or piece 5. The two poles have the pole faces 6 and 7 spaced from and facing each other. Wound on the poles'3 and 4 are the windings 8 and 9, respectively, connected in series or parallel. This construction of the magnet 2 produces a magnetic field flowing between the two pole faces 6 and 7 and having a path through the poles 3 and 4 and the magnetic cross piece 5.

Between the two faces 6 and 7 is located the chute 10' having its lower end located immediately between the faces 6 and 7 and its upper end extending upwardly. Thev upper end is flared outwardly to provide a funnel portion 1 1 for receiving magnetizable objects.

Mounted on the pole piece 4 is a bracket 12 supporting a Syntron feeder 13 provided for distributing the articles evenly while they are being conveyed to the chute receiving portion 11.

A skip hoist 20 is provided for conveying the nails up-- wardly and dumping them into the Syntron feeder 13. This skip hoist includes the upright support member 21 and the inclined support track 22. Located at the top of the skip hoist is the motor 23. The track 22 guides; the bucket 24 as it is pulled upwardly by motor 23. FIG. 1 shows the bucket 24 in dumping position above they Syntron feeder 13. The lower position is shown in phantom. This entire dumping and distributing apparatus is disclosed and claimed more specifically in the copending application SN 836,230 filed August 26, 1959 and. entitled. Automatic Nail Processor and Packager.

Below the chute 10 is a platform 30 which is actuated upwardly and downwardly by the fluid motor 31. This platform is adapted to receive a box 32 which when raised by the platform is telescoped over the lower end section of chute as shown in more detail in FIG. 2.

;-'. In accordance with the basic operation of this apparatus when the box is lifted upwardly into telescoping rela tionship with the lower end of chute 10, a switch is actuated which energizes the windings 8 and 9. These windings are connected together and constitute a single winding means which when the current flows in one direction itflows through the entire windings and when the current is reversed it flows through the entire windings in the reverse direction. When the current is flowing through the windings in the so called forward direction a magnetic field is created between the pole faces 6 and 7. The flux of this field is sufficiently strong to suspend a plurality of nailsitherebetween, the nails being arranged in parallel relationship. The magnetic field is sufficiently strong so that several row of nails or other objects can be suspended between the two faces, as illustrated by FIG. 2.

Difficultyexperienced by other machines of this type is that when the electromagnet is demagnetized the nails farther away from the faces 6 and 7 tend to drop immediately. Further, the nails rather sag downwardly as the electromagnet is demagnetized and as a result the nails lose their parallel orientation. In accordance with this invention there is provided a demagnetization system which in combination with the apparatus just described eliminates this disorientation of the nails. This demagnetization system will now be described particularly with relation to FIG. 3.

FIG. 3 shows a control circuit for the demagnetization of-the electromagnet 2. This control circuit is connected to a 440 volt supply and includes the rectifier DC. power supply 40 which produces a DC. voltage of 250 volts. Leading from the rectifier 40 are the two lines 41 and 42, and connected between these two lines, parallel with each other, are several circuits. These circuits include the reverse control circuit 50, the forward control circuit 69, the inductive timer circuit 70, and the electromagnet energizing circuit 80. The reverse control circuit includes the relay coil R, the relay contact switch ID, the normally closed contact switch CR and the normally closed contact switch Fb, all connected in series. Shunting the relay contact switch CR is the relay contact switch Ra. 1 The forward control switch 60 includes the relay coil F, the switch S, the timer, and the normally closed relay contact switch Rb, all connected in series. Connected parallel with the switch S and relay coil F is the relay coil A connected in series with the relay contact switch [liq-which in turn is shunted by the relay contact switch The inductive timing circuit 70 includes two lines '71 and 72 connected in parallel between the lines 41 and 42. Connected in series in the line 71 is the relay contact switch Ab and the main coil 73 of the inductive timing relay TD. Connected in series in the line 72 is the rheostat 75 connected in series with the neutralizing coil 74 of the inductive timing relay and also the series resistance The electromagnetic energizing circuit includes the windings 8 and 9 connected in series with the ammeter 82 and the relay coil CR. Shunting these three components is the discharge resistance 83.

The circuit is completed by the two relay contacts Fe diagram that the relay coil R controls the opening and closing of the relay contact switches Ra, Rb, Rc and Rd. Similarly, relay coil F controls the opening and closing 4 of the relay contact switches Fa, Fb, Fe and Fd. The relay coil A controls the opening and closing of the relay contact switches Aa and Ab, and relay coils 73 and 74 control the opening and closing of the contact switch TD. The switch S is opened and closed either manually or automatically when the box 32 is in position between pole faces 6 and 7.

Operation In the operation of this apparatus, the box 32 is lifted by platform 30 into telescoping relationship with the lower end of the chute 10 and in that position is ready to, receive the nails or other magnetizable objects. When this occurs, the switch S is closed either automatically or manually. Upon closing switch S the relay F is energized. This opens the relay contact switch Fb located in the reversal control circuit and prohibits the operation of the reversal control circuit.

At the same time the contact switches Fa, Fe and Fd are closed which energizes the windings 8 and 9. When Fa is closed the relay coil A is energized which in turn closes the two relay contacts Aa and Ab closing the circuit' through the inductive timing relay TD energizing both the main coil 73 and the neutralizing coil 74.

Energization of the electromagnet windings 8 and 9 creates a magnetic field or flux between the two pole faces 6 and 7. Upon creation of this field, the articles are dumped into the chute 10 via the skip hoist 20 and the "Syntron feeder 13. The articles fall downwardly through the chute and are arranged or oriented in parallel relationship between the two pole faces 6 and 7. These articles are held in suspension within the lower end of the chute while'the electromagnet is energized by the forward relay F.

After a predetermined time determined by the timer, the circuit through the relay coil F is opened which in turn causes the relay contact switches Fa, Fe and Fd to open and the normally closed switch Fb to close. Upon opening these two switches and cutting off power to windings 8 and 9, the windings discharge through the discharge resistance 83 until a predetermined value of current is reached at which time the relay coil CR is sufiiciently deenergized to cause the normally closed relay contact switch CR to close. As a result, the circuit through the reverse control circuit 50 is closed energizing the relay coil R. This closes the relay contact switches Ra, R0 and Rd thus closing the circuit through the windings but with the current flowing in the opposite direction. As a result the current causes the electromagnet to demagnetize quickly. This demagnetization occurs so quickly thatthenails all drop together in parallel relationship.

During this reverse flow of current the relay coil R maintains the normally closed relay contact switch Rb opened preventing thesimultaneous operation of both the reversal and forward control circuit.

The opening of the relay contact switch Rb deenergizes the relay coil A which in turn opens the circuit to the main coil 73 of the inductive timing relay TD. This drops out the main coil and the neutralizing coil starts to decay. After a predetermined delay time, the relay switch TD in the reverse control circuit opens. This delay time isadjustable by the adjustment of the rheostat 75 which sets the strength of the neutralizing coil.

FIGS. 4 and 5 show a time graph of the voltages and current measured on the volt meter 43 and the ammeter 82. It will be seen that the first voltage impressed whenswitch S is closed has a positive value of 250 volts during the so called MAG time during which the electroma net is magnetized for orienting the magnetizable articles.- The MAG time interval is of very little significance The significant time interval is the DEMAG during which time the electromagnet is demagnetized causing the nails or other articles to fall downwardly to the bottom. of the carton or container. If this DEMAG time interval is too long the nails will sag and be disorientated; It will be noted that in accordance with this invention the.

"DEMAG time interval includes the time interval indicated by X and Y. During the X time interval the voltage is falling and the current is discharging through the discharge resistance 83. At the time indicated by reference numeral Z, the coil relay CR becomes sulficiently deenergized to close the relay contact switch CR and bring into operation the reversal control circuit 50. During the Y time interval the voltages and amperage value quickly transfers to the opposite side of the zero line, thus reversing the polarity of the electromagnet. This quick reversal cuts the DEMAG time interval by seconds as will be observed by broken line showing the normal decay of the current in the windings.

The arrangement of the demagnetizing circuit facilitates almost an instantaneous demagnetization of the electromagnet and accordingly substantially an instantaneous drop of the articles into the container with very little sag or disorientation during the drop.

Having described my invention, it should become 0bvious that although I have shown and illustrated a preferred form of this invention, alterations and modifications thereof are possible within its spirit. Accordingly, this invention is to be limited only as set forth by the express language of the appended claims.

Having regard to the foregoing disclosure, the patent of which this specification forms part confers, subject to the conditions prescribed in the Patent Act, 1935, the exclusive right, privilege and liberty of making, constructing, using and vending to others to be used, the invention as defined in claims submitted by the patentee as follows:

1. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, at single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval suflicient to permit orientation of the objects in the chute; means thereafter operative to shut ofl flow of current in said one direction; means for discharging the current from said Winding means; means responsive to a predetermined decrease in the current flowing in said one direction through said winding means for operatively producing a flow of current through said winding means in said reverse direction whereby the demagnetization of said electromagnet is accelerated.

2. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; means for discharging the current from said winding means; means responsive to a predetermined substantial decrease (proximating zero) in the current flowing in said one direction through said winding means for producing a flow of current through said winding means in said reverse direction whereby the demagnetization of said electromagnet is accelerated.

3. Apparatus for packaging magnetizable objects com,- prising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects be-' fore they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to pro duce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; timer switch means thereafter operative to shut off flow of current in said one direction; means for discharging the current from said windings; means responsive to a predetermined decrease in the current flowing in said one direction through said winding means for operatively producing a flow of current through said winding means in said reverse direction whereby the demagnetization of said electromagnet is accelerated.

4. Apparatus for packaging magnetizable objects com prising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; a discharge resistor means shunting said winding means for discharging the current thereof; means responsive to a predetermined decrease in the current flowing in said one direction through winding means for operatively producing a flow of current through said winding means in said reverse direction whereby the demagnetization of said electromagnet is accelerated.

5. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single windingmeans for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said Winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; means for discharging the current from said winding means; a reversing circuit for reversing the flow of current through said winding means to reverse the polarity thereof, a relay means having contact means located in said reversing circuit and a coil located in the circuit of said windings; said coil being responsive to a predetermined decrease in current flowing through said windings in said one direction to close said contacts whereby the reversing circuit is closed and the electromagnet is demagnetized.

6. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects, before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; means thereafter operative to shut oflf flow of current in said one direction; means for discharging the current from said windings; a reversing circuit arranged to cause reversing of the flow of current through said winding means; relay coil means arranged to control the oper ation of said reversing circuit; said relay coil means being responsive to the flow of current in said one direction through said winding means as said current decays to a predetermined value proXima-ting zero whereby said reversing circuit is operated to cause reversal of the current flowing through said winding means.

7. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; a reversing circuit arranged to cause reversing of the flow of current through said winding means; relay coil means arranged to control the operation of said reversing circuit; said relay coil means being responsive to the flow of current in said. one direction through said winding means as said current decays to a predetermined value whereby said reversing circuit is operated to cause reversal of the current fiowingthrough said winding means, and a discharge resistor means shunt-' ing said winding means and relay coil for discharging the current thereof.

8. Apparatus for packaging magnetizable objects comprising a chute through which the objects are de1iv-' ered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufficient to permit orientation of the objects in the chute; timer switch means thereafter operative to shut off flow of current in said one direction; means for discharging the cur: rent from said winding means; a reversing circuit arranged to cause reversing of the flow of current through said winding means; relay coil means arranged to control the operation of said reversing circuit; said relay coil means being responsive to the flow of current in said one direction through said winding means as said current decays to a predetermined value whereby said reversing circuit is operated to cause reversal of the current flowing through said winding means.

j 9. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to pro duce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval sufiicient to permit orientation of the objects in thechute; timer switch'means thereafter operative to shut olf flow of cur- 8 rent in said one direction; a reversing circuit arranged to cause reversing of the flow of current through said winding means; relay coil means arranged to control the operation of said reversing circuit; said relay coil means being responsive to the flow of current in said one direction through said winding means as said current decays to a predetermined value whereby said reversing circuit is operated to, cause reversal of the current flowing through said winding means, and a discharge resistor means shunting said winding means and relay coil for discharging the current thereof.

10. Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to pro duce a field of given polarity and also arranged to conduct current in the reverse direction for energizingthe electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval suificien-t to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; means for discharging the current from said winding means; means responsive to a predetermined substantial decrease (proximating zero) in the current flowing in said one direction through said winding means for producing a flow ofcurrent through said winding means in said reverse direction whereby the demagnetization of said electromagnet is accelerated, and an inductive timing means for controlling the time interval of flow of current through said winding means in said reverse direction.

11. Apparatus for packaging magnetizable objects comprising a chute through which the objects are del1v ered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to-reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval suflicient to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; means for discharging the current from said winding means; means responsive to a predetermined decrease in the current flowing in said one direction through said winding means for operatively producing a. flow of current through said winding means in said reverse direction whereby the demagnetization of said electromagnet is accelerated, and an inductive timing means for controlling the time interval of flow of current through said winding means in said reverse direction.

' 12 Apparatus for packaging magnetizable objects comprising a chute through which the objects are delivered to an empty container, an electromagnet for producing a magnetic field across the chute to orient the objects before they are received in the container, a single winding means for the electromagnet adapted to conduct current in one direction for energizing the electromagnet to produce a field of given polarity and also arranged to conduct current in the reverse direction for energizing the electromagnet to reverse the polarity thereof; means operative to produce a flow of current through said winding means in said one direction for a time interval; sufiicient to permit orientation of the objects in the chute; means thereafter operative to shut off flow of current in said one direction; means for discharging the current from said winding means; a reversing circuit arranged to; cause reversing of theflow of current through said windingmeans; relay coil means arranged to control the operation of said reversing circuit; said relay coil means being responsive to the flow of current in said one direction through said Winding means as said current decays to a predetermined value whereby said reversing circuit is operated to cause reversal of the current flowing through said windings, and an inductive timing means for controlling the time interval of flow of current through said Iwinding in said reverse direction.

References Cited in the file of this patent UNITED STATES PATENTS Jaeger Mar. 17, Hudson Aug. 4, Connoy Mar. 26, Gilbert Oct. 22,

Otto Aug. 18, 

